The hedge fund that has called on Sony to list part of its profitable entertainment arm has boosted its stake in the company, a report said Tuesday, days ahead of a shareholders\' meeting. Billionaire investor Daniel Loeb, who last month proposed hiving off up to 20 percent of the division, which includes music and movies, said his Third Point LLC fund had since added another five million shares, taking its stake to seven percent. In a new letter to Sony boss Kazuo Hirai, carried by the Wall Street Journal on Tuesday, Loeb says the division lacks the \"discipline and accountability\" of its competitors and would benefit from a listing. \"It seems difficult to argue that Entertainment would not be strengthened by the transparency that comes with public reporting, an active media analyst community evaluating financial performance regularly, and an expert board with strongly aligned incentives,\" the letter said. Sony, like many Japanese companies that came of age in the booming Japan of the 1970s and 1980s, diversified its operations to include seemingly unrelated businesses with few synergies. Critics say this has left them too big to cope with their more nimble overseas competitors and has led to years of profit bleeding. Despite having taken a particularly bad beating in the sector, the firm has repeatedly reiterated its commitment to producing televisions and other home electronics. In his more recent letter, Loeb -- an outspoken investor with a reputation for pushing change at the companies he targets -- suggested Hirai serve as head of the board of the new business, while retaining his spot at the helm of the overall group. He also repeated his offer of service on Sony\'s board, noting the size of his fund\'s stake in the company. In May, Hirai said the board would examine Loeb\'s proposal, despite having previously said the entertainment arm of Sony was not for sale. The company\'s annual shareholder meeting is being held in Tokyo on Thursday. \"As previously stated, Sony\'s board of directors will conduct an appropriate review of Third Point\'s proposal. We aren\'t commenting on specifics of their proposal,\" the company said in a statement Tuesday. In the fiscal year to March, Sony reported its first annual net profit in five years, although it was largely driven by a weakening of the yen -- which boosts the value of its repatriated foreign income -- and a string of asset sales including unloading its Manhattan headquarters. Hirai has said he is on track to bringing Sony\'s money-losing television business into profitability. Sony\'s Tokyo-listed shares were up 4.51 percent to 2,039 yen in afternoon trading.